Method and apparatus for ultrarapidly charging a battery

ABSTRACT

A method and apparatus for ultrarapidly charging primary or secondary battery. Charging current is multiple-frequency complex pulse current which is comprised of pulse current overlapped by pulse current with at least two different frequency band and arbitrary waveform and opposite narrow pulse whose amplitude is three times higher than amplitude of said pulse current. The charging current may be larger than 1.5C10 and charging is performed in a manner of no discharging. Charging circuit is comprised of at least two different frequency oscillators, switch circuit and opposite narrow pulse generating circuit. The pulse current of different frequency may overlap each other, modulated and scanned and varied on frequency to generate multiple-frequency complex charging current.

TECHNICAL FIELD

The present invention relates to a method and apparatus for charging aprimary or secondary battery, in particular a method and apparatus forrapidly charging a battery using multiple-frequency composite pulsecurrent without a discharging process.

TECHNICAL BACKGROUND

In a conventional battery charging method, a direct current of 0.lC10 isused to charge a battery for 12-16 hours. Although this method is safeand reliable, it has many defects such as accumulation of polarization,memory effect and very long charging time. In the Chinese Utility Model91208037.X, the applicant of the present invention described a rapidlycharging apparatus which uses "surge multi-wave group pulsating voltagesource" to charge a variety kinds of chemical batteries. It diminishessome of the memory effect, but its charging time is more than an hour,which is too long.

In the prior art, there exists a negative pulse charging method, namedreciprocating charging method, i.e., charging a Ni-Cd battery with asingle pulse current for a duration, then initiating a dischargingcircuit with a inverted pulse (this pulse is not applied to the batteryto be charged) to discharge the battery with a large current in a shorttime, then repeat the charging and discharging, in this way, cyclicallyrepeating the charging and discharging process until the battery isfull. This typical charging method can be found in Hungary Patent No.189, 832, of which the application in China is No. 87108081 (ExaminedPublication No.CN100643313), and this method has the advantageous effectof depolarization.

There are many patent applications similar to the above method, but noneof them depart from the reciprocate manner of cyclicallycharging-discharging-charging-discharging.

These methods are a significant improvement compared with theconventional method of slow charging, however, they have not solved theproblem that the Ni-Cd battery produces memory effect and the effect ofde-polarization is not complete. Now the commercial available chargerfor Ni-Cd battery which are most excellent in performance and expensivein price must be added a separate device special for discharging, whichperforms discharging each time before charging, and after the battery isdischarged to empty, proceeds automatically to charging operation. Thisseparate discharging process is different from the discharging cycles inthe reciprocate-charging process in that it is a forced large currentdischarging before the start of charging, and the purpose thereof is toprevent the battery from unchargeable status due to the memory effectwithin the battery. Furthermore, this charging method can not be used tocharge a primary battery.

The object of the present invention is to provide a improved method andapparatus for rapidly charging battery, which use multiple-frequencycomposite pulse large current to perform charging without dischargingprocess so as to eliminate memory effect and shorten the charging time.

SUMMARY OF THE INVENTION

The charging method of the present invention has the following mainfeatures:

The charging current is a multiple frequency composite pulse current,which is formed by at least two pulse currents with different frequencybands and arbitrary waveforms overlapped each other, and an invertedsharp pulse, whose amplitude is at least three times higher than that ofsaid pulse current, overlapped thereon; the charging current can usevery large capacity, which may be 1-l.5C10 or more than 1.5C10; chargingis performed in a manner of charging all the time without dischargingprocess.

The charging apparatus of the present invention includes a chargingcircuit for generating multiple frequency composite pulse current, andthis charging circuit comprises:

at least two oscillators of different operating frequencies forgenerating pulse signals within different frequency bands;

a switch circuit connected between a charging power source and chargingterminals of the battery for controlling the on/off of the chargingcurrent, and the controlling terminals thereof are connected in parallelwith the respective outputs of said at least two oscillators to generateoverlapped multiple frequency pulse signal;

an inverted sharp pulse generating circuit defined by a pulse shapingcircuit formed by inductors, capacitors and resistors connected to saidswitch circuit for generating inverted sharp pulses of which theamplitude is at least three times higher than that of said over-lappedpulse current.

Alternatively, the charging circuit of the present invention can useanother kind of oscillators and switch circuit, i.e., comprising:

two oscillators of different operating frequencies, wherein the outputof one oscillator modulates the other one for generating modulatedmultiple frequency composite pulse signal;

a switch circuit connected between a charging power source and chargingterminals of a battery for controlling the on/off of the chargingcurrent, the controlling terminals thereof are controlled by themodulated multiple composite pulse signal generated by said oscillators.

The charging method and apparatus of the present invention are based ona complete new charging mechanism, thereby have significant advantageouseffects that various primary or secondary batteries can be really fullycharged in 15-30 minutes.

In the present invention, it is a innovation to the characteristic ofthe charging current that the charging current flowing into the batteryis a group of pulses of multiple frequencies and multiple waveformswhich have a great capability of disturbing. The charger designedaccording to the present invention has a powerful-polarization effectand can significantly refrain from the memory effect of Ni-Cd battery;automatically eliminate the memory effect which has already generated;and refrain from the generating of harmful gas and prevent from or delaythe producing of metal deposits. Accordingly, it can be realized thatprimary batteries can be made really rechargeable.

The charger according to the present invention does not need the specialdischarging device before charging, and there are not discharge cyclesin the charging process, i.e., the battery being charged is only chargedwithout discharging process. This is the first unique feature of thepresent invention.

The multiple frequency multiple waveform pulse group and inverted peakhigh voltage sharp pulse generating techniques are used in the presentinvention, wherein high and sharp pulses of which the amplitude is atleast three times higher than that of the fundamental wave are mixedamong the group of pulses. This kind of surge current flows into thebattery to be charged and applies a powerful effect of disturbance,thereby the distribution of the ions on the surface of the electrodes ofthe battery is even, while the harmful grains of metal atom deposit arenot easy to form, and the potential energy of each point on theelectrodes is changed rapidly as the turbulence of the current andreaches an even status in a short time, therefore the memory potentialbarrier of the Ni-Cd battery can be disturbed. Meanwhile, the generatingof the reaction deposit of a primary battery can be refrained from ordelayed, accordingly, the really charging to primary batteries can berealized by means of the apparatus of the present invention. When aprimary battery has not been used to beyond its fatigue limit (i.e. itsinternal resistance has not apparently increased), it can be charged andreused repeatedly. This is the second unique feature of the presentinvention. It was proved by experiments that the stronger thisdisturbing effect is, the better the charger is. One of the importantimprovements of the present invention is that frequency-sweep pulses areadded. The addition of the frequency-sweep pulses to the firstfundamental wave or second fundamental wave results in a more powerfuldisturbing capability of the composite pulse group, and a more evendisturbing effect, consequently, it will not cause the local overheatingof the battery and generate harmful gas, and the distribution of ions onthe surface of the electrodes is more fine and more even.

Under the above conditions of the charging current, the battery to becharged can endure the charging current of very large capacity,therefore, with the charging method of the present invention, chargingcurrent 1-1.5C10 or more than 1.5C10 can be used for charging, and thecharging time are significantly shortened.

Since there is not discharging process during the whole chargingprocess, the charger according to the present invention has higherefficiency, shorter charging time, and it can charge the battery tofully charged or over charged to 120% (overcharged to 120% is useful tothe battery because the Ni-Cd battery is easy to self-discharge) in avery short time, and it is not necessary to charge the battery to 80%first, then charge it with trickle current for the rest, like thecharger available in the market. This is the third unique feature of thepresent invention.

BRIEF DESCRIPTION TO THE DRAWINGS

The embodiments of the present invention are described in detail asbelow.

FIG. 1 is a general principle block diagram of the present invention;

FIG. 2 is a circuit diagram of a first embodiment;

FIG. 3 is a circuit diagram of a second embodiment;

FIG. 4 is waveform diagrams of related measuring points of the circuitof related measuring points of the circuit of the first embodiment;

FIG. 5 is a circuit diagram of a third embodiment;

FIG. 6 is waveform diagrams of related measuring points of the circuitof the third embodiment.

FIG. 7 is a circuit diagram of a fourth embodiment.

DETAILED DESCRIPTION TO THE INVENTION

Accompanying FIG. 1 is the general principle block diagram. Only thecore portion of the charging principle, "multiple frequency multiplewaveform composite pulse group voltage source" is described in detailbelow, the related peripheral circuits such as voltage-reducingrectifier circuit, timing circuit, display circuit, and protectioncircuit are omitted. The whole circuit comprises a first fundamentalwave oscillator A!, a second fundamental wave oscillator B! and anelectronic switch K!. Each of A! and B! has an valid operating frequencyrange. A! is a pulsating wave of any frequency within 0.1-60 HZ, and theoptimal frequency range thereof is 1-15 HZ; and B! is pulsating wave ofany frequency within 61 HZ-5000 HZ, and the optimal frequency rangethereof is 80-150 HZ. The above two waveforms may be arbitrary, and thefrequencies thereof may be constant frequency, or sweep frequency. Bothwaves may be mixed directly at the base (or control terminal) of theswitch transistor K! (the switch S is coupled to I), or A! wave is usedto modulate B! wave (or opposite) first, then the modulated wave isapplied to K! (the switch S is coupled to II). In both cases, it iscommon to use composite pulse wave group to control the switching statusof K!,so that the output voltage of the charger varies dependent uponthe composite waveform at the input of K!, thereby the charging currentis forced into the battery to be charged according to the predeterminedwaveform. K! through L can be connected in parallel with the twoterminals of the power source (as a branch), or in series with the powersource (as a resistance). In the case of parallel connection, when K! ison, i.e., the power source is short-circuited, no current flows into thebattery; when K! is off, all the current from the power source isapplied to the battery to be charged.

The DC resistance of the inductor L is small so as to be equivalent toshort circuit to a direct current, while the inductance thereof isrelative large (1 mH), and its impedance to AC is very high. Theinductor L, together with the resistor R and capacitor C, generatesinverted peak sharp pulse of which the amplitude is at least three timeshigher than that of the fundamental wave in the group of composite pulsewaves, so as to effective refrain from the generation of the harmful gaswithin the battery and the memory effect, and possess strongdepolarization effect. Only with this kind of charging current can thebattery endure the charging current of very large capacity withoutcausing generating of gas, heating and high pressure in the batteryduring the period until the battery is charged to full. Accordingly, thebattery can be once over-charged to saturation in short time with largecurrent, i.e., charging current of 1-1.5C10 or more than 1.5C10, whilethe supplementary charging with trickle current is no longer necessary,and the primary batteries can become really rechargeable, which isimpossible for the conventional charging method.

FIG. 2 is the circuit diagram of the first embodiment of the presentinvention.

The oscillators A! and B! are formed by OR NOT gate IC1 (CD4001B),wherein H1 and H2 form the first fundamental wave oscillator A!, and thetested frequency thereof is 6 Hz (measured when H3, H4 aredisconnected); H3 and H4 form the oscillator B!, and the testedfrequency thereof is 200 HZ (measured when H1, H2 are disconnected). Theoutput pin (4) of A! is applied to the input pin (8) of B!, to modulateB!, then the modulated composite waveform (see the waveform diagram attest point (c) in FIG. 4) is applied via a buffer resistor R4 (33K) tothe base of the switch transistor BG1. BG1 forms a electronic switch K!,of which the two terminals are connected through the inductor L1 of 1mH) in parallel with the positive and negative electrodes of the powersource. When BG1 is turned on, which is equivalent to short-circuitingthe power source, no current flows through the battery being charged;when BG1 is turned off, all the current from the power source areapplied to the battery. The 1 mH inductor L1 has a small DC resistance,which can be deemed short-circuit for DC, while the inductor L1 has ahigh AC impedance, and together with the shaping filtering capacitorsC3, C4 and resistor R5 causes a high amplitude inverted peak sharp pulseapplied to the composite pulse voltage so that the generation of gas andthe memory effect within the battery can be effectively refrained from.D1 is a medium power rectifier diode, which allows one-direction currentand prevent from the opposite-direction current flowing, so as toprevent the charging voltage from applying to the charger circuit fromthe opposite direction. R5 is a shaping and current-limiting resistor,of which the resistance value can be changed to adjust the chargingcurrent up to 1.5C10. In this embodiment R5 is 10Ω, and the chargingcurrent is 500 mA.

When no load, the output waveform at point (e) is shown in FIG. 4; it isa most unique feature of the present invention.

FIG. 3 is the circuit diagram of embodiment 2.

Gate circuits H5, H6 form the first fundamental wave oscillator A!, andH7, H8 form the second fundamental wave oscillator B!, the oscillatingfrequencies thereof are the same as in embodiment 1, respectively. Whatis different from embodiment 1 is that the inputs of A! and B! (i.e.,inputs of H5 and H7) are connected together, the outputs of H6 and H7are both applied to the input of the inverter H8, and the compositepulsating wave group are obtained at the output of H8. The electronicswitch K! (BG2) is controlled by means of a buffer resistor R1 (33K).The other parts and their operation are the same as embodiment 1, andthe waveforms of the test points are corresponding to that in embodiment1.

FIG. 4 shows the waveforms of test points.

(b) shows the waveform output of A! in FIG. 2 A!

(c) shows the wave form output by B! in FIG. 2 B!

(e) shows the waveform of the general output when no load (no batterymounted) in FIG. 2, which is the unique waveform of the presentinvention.

(f) shows the waveform of the general output when charging a battery(locally enlarged)

(i), (j) are waveforms of the input and output of H8 in FIG. 3,respectively.

FIG. 5 is a circuit diagram of embodiment 3. This is a kind of sweepfrequency overlapping circuit.

The first fundamental wave oscillator A! comprises light emit diode LEDand current-limiting resistor R21, the fundamental oscillating frequencythereof is 5 HZ and it outputs a single rectangular wave, which iscoupled to the base of the switch K! BG3 by means of R22, C14. Thesecond fundamental wave oscillator B! comprises a fundamentalrectangular wave oscillator formed by phase lock loop integrationcircuit IC2 CD4046B and its peripheral circuits, the oscillatingfrequency thereof is 200 HZ. As the capacitor C11 is connected to theinput pin 9 of the voltage controlled oscillator VCO, so that when theelectronic switch BG2 is turned on, C11 is charged by the power sourcethrough R16, thereby the voltage of C11 is increased gradually from 0,resulting in the frequency of the pulse waves at the output pins 3, 4 ofCD 4046B scans from low to high; when the switch BG2 is turned off, C11is discharged through R17, the frequency of the pulse waves at theoutput of CD4046B scans from high to low. This frequency sweep wave iscoupled by C13 to the base of BG3, and mixed with the relatively highamplitude single pulse low frequency wave output from the oscillator A!to form a multiple composite pulse group, so as to control the on/off ofthe switch transistor BG3 and output the amplified strong disturbingmultiple frequency multiple waveform pulse group at the collector ofBG3. By means of the combination of inductor L2, resistor R23 andcapacitors C15, C16, an inverted peak sharp pulse of which the amplitudeis at least three times higher than that of the fundamental wave isformed, and these strong disturbing composite pulse groups are appliedto the battery to be charged via an invert-preventing diode D4. Theexistence of D4 results in that the battery can be only charged and cannot be discharged, thereby the charging efficiency is significantlyincreased, the charging time is shortened, and the energy consumingduring charging is decreased. IC3555 forms a flip-flop, of which the 3pins output switching pulses with duty cycle of 1:1 when power turnedon, i.e., the high level duration is 0.5 minute, and the low levelduration is 0.5 minute. This signal controls the on/off of BG2, turnedon for 0.5 minute, and turned off for 0.5 minute.

FIG. 6 shows the waveforms of the test points in FIG. 5, in which (k) isthe output waveform of oscillator A!; (1) is the output waveform ofoscillator B!; (m) is the general output waveform without the battery.As shown in these waveforms, among the low frequency large ripple wavesthere are mixed high frequency small ripple waves, and among these twocomposite waves there are sharp and narrow pulses of which the amplitudeis several times as much as theirs. As shown in this figure, comparedwith FIG. 4. The pulse wave is a sweep frequency modulated wave. This isthe core of the present invention: the waveform of multiple frequencymultiple waveform composite pulse group voltage source, which is themost unique feature different from all the conventional charger. Thisunique waveform can be measured with a normal oscilloscope connected tothe output of the charger (without load), therefore it is the uniquefeature of the present invention.

FIG. 7 is the circuit diagram of embodiment 4. This embodiment is amodulated sweep pulse group generator.

The first fundamental wave generator A! is a triangular wave generatorformed by two operating amplifiers IC4 TL082, of which pin 7 outputscontinuous triangular wave with frequency of 1 HZ. The secondfundamental wave oscillator B! is a frequency sweep signal generatorformed by a voltage controlled oscillator (VCO) of IC5 LM331, of whichthe center frequency is determined by R30, R31, R32, and C19, C20, inthe present embodiment, the center frequency is 180 HZ, and under thecontrol of the triangular wave output from the pin 7 of IC4, the VCO ofIC5 generates sweep signal of 100-260 HZ. The modulated amplifiedcomposite pulse group in this frequency-sweep range is output from pin 3of IC5, and applied to the input of switch transistor BG4. The processthereafter is the same as embodiment 1, and the description thereof isomitted.

We claim:
 1. A method for rapidly charging a battery comprising couplingto said battery a composite charging current that includes a first pulsetrain whose frequency is within a range of 0.1 Hz to 60 Hz, a secondpulse train whose frequency is within a range of 61 Hz to 5,000 Hz, anda third pulse train of inverted narrow-width pulses whose amplitude isat least three times greater than an amplitude of a combination saidfirst pulse train and said second pulse train;wherein said compositecharging current charges without discharging said battery.
 2. The methodof claim 1, wherein said composite current has at least onecharacteristic selected from the group consisting of (a) said firstpulse train has a frequency in a range of 1 Hz to 15 Hz, and (b) saidsecond pulse train has a frequency in a range of 80 Hz to 250 Hz.
 3. Themethod of claim 1, wherein said composite current has at least onecharacteristic selected from the group consisting of (a) said firstpulse train has a swept frequency, (b) said first pulse train has aconstant frequency, (c) said second pulse train has a swept frequency,and (d) said second pulse train has a constant frequency.
 4. The methodof claim 1, wherein said composite current comprises only sweptfrequencies.
 5. An apparatus for rapidly charging a battery, including:acomposite charging current circuit that provides a composite chargingcurrent and includes: a first oscillator that provides a first pulsetrain whose frequency is within a range of 0.1 Hz to 60 Hz; a secondoscillator that provides a second pulse train whose frequency is withina range of 61 Hz to 5,000 Hz; a switch circuit coupled between a sourceof charging power and charging terminals of said battery to control anon and off state of said charging current, said switch current alsocoupled to output terminals of said first oscillator and said secondoscillator to present generated overlapping multiple frequency currentpulse signals therefrom; an inverted sharp pulse generator circuit,comprising at least an inductor, a capacitor, and a resistor, coupled tosaid switch circuit to generate a train of inverted narrow-width pulseswhose amplitude is at least three times greater than an amplitude of acombination said first pulse train and said second pulse train; whereinsaid composite charging current charges without discharging saidbattery.
 6. The apparatus of claim 5, wherein said composite chargingcurrent circuit has at least one characteristic selected from the groupconsisting of (a) said first frequency has a range of 1 Hz to 15 Hz, (b)said first frequency is swept, (c) said first frequency is constant, (d)said second frequency has a range of 80 Hz to 250 Hz, (e) said secondfrequency is swept, and (f) said second frequency is constant.
 7. Theapparatus of claim 5, wherein said composite charging current circuithas at least one characteristic selected from the group consisting of(a) said first pulse train modulates said second oscillator to vary saidsecond frequency, and (b) said second pulse train modulates said firstoscillator to vary said first frequency;wherein said composite currentincludes modulated multiple frequencies.
 8. The apparatus of claim 7,wherein said composite charging current circuit has at least onecharacteristic selected from the group consisting of (a) said firstfrequency has a range of 1 Hz to 15 Hz, (b) said first frequency isswept, (c) said first frequency is constant, (d) said second frequencyhas a range of 80 Hz to 250 Hz, (e) said second frequency is swept, and(f) said second frequency is constant.
 9. The apparatus of claim 5,wherein said apparatus is useable in at least one environment selectedfrom the group consisting of (a) an independent battery charger, and (b)a battery charged included with an electronic device.
 10. The apparatusof claim 6, wherein said apparatus is useable in at least oneenvironment selected from the group consisting of (a) an independentbattery charger, and (b) a battery charged included with an electronicdevice.
 11. The apparatus of claim 7, wherein said apparatus is useablein at least one environment selected from the group consisting of (a) anindependent battery charger, and (b) a battery charged included with anelectronic device.
 12. The apparatus of claim 8, wherein said apparatusis useable in at least one environment selected from the groupconsisting of (a) an independent battery charger, and (b) a batterycharged included with an electronic device.